1. Field of the Invention
The present invention relates to a steering control apparatus, a steering control system and a steering control program for controlling a steering angle of a vehicle, particularly to those for controlling a steering angle of a vehicle in which a steer-by-wire is employed and a torque is separately provided for each steered wheel.
2. Description of the Related Art
As disclosed in JPA H07-125643, there has been known a “steer-by-wire (SBW)” in which a mechanical connection between a steering wheel and steered wheels of a vehicle is eliminated. In a vehicle employing the SBW technique, a sensor detects steering amount of a steering wheel, based on which steered wheels are steered by using a motor or motors, or by using a hydraulic mechanism.
In such a conventional technique, an actuator dedicated to steering (also referred to as a “steering actuator”) such as a motor or a hydraulic mechanism is required as a power source for steering the steered wheels. Consequently, spare space for other components of the vehicle is restricted so that a steering-relevant design is constrained.
Therefore, in the light of such a disadvantage, it has been target to provide a steering control apparatus, a steering control system and a steering control program in the SBW scheme, which eliminates a steering actuator, thereby to enhance flexibility of the steering-relevant design.